Drill string with aluminum drill pipes, bent housing, and motor

ABSTRACT

Methods and apparatuses include drilling a bore hole in a horizontal direction with a drill bit, a bent housing portion, and a mud motor by rotating the drill bit, the bent housing portion, and the mud motor with drill pipe comprising an aluminum pipe section. The methods and apparatuses also include stopping rotation of the drill pipe and performing a slide by rotating the drill bit with the mud motor to advance the drill bit, the bent housing portion, the mud motor, and the drill pipe in the borehole so that the aluminum pipe section moves axially along the bore hole in the horizontal direction. The methods and apparatuses also include continuing to drill the bore hole by rotating the drill bit, the bent housing portion, and the mud motor with the drill pipe.

PRIORITY DATA

The present disclosure claims priority to and the benefit of the filing date of U.S. Provisional Application 61/835,319, filed Jun. 14, 2013, incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

Underground drilling involves drilling a bore through a formation deep in the earth using a drill string including a drill bit connected to drill pipe. During rotary drilling, the drill bit is typically rotated by a top drive or other rotary drive means at the surface, where a quill and/or other mechanical means connects and transfers torque between the rotary drive mechanism and the drill string. During drilling, the drill bit is rotated by a drilling motor mounted in the drill string proximate the drill bit, and the drill string may or may not also be rotated by the rotary drive mechanism.

Drilling operations may begin in the vertical direction, but are frequently steered to drill in a horizontal direction. When drilling in the horizontal direction, the weight and length of the drill string lies against the bottom side of the horizontally drilled hole. As the drill string lengths become longer and longer in the horizontal direction, the friction and resistance to rotation and axial advancement becomes greater and greater.

Various systems and techniques can be used to perform vertical, directional, and horizontal drilling. For example, steerable systems use a drilling motor with a bent housing incorporated into the bottom-hole assembly (BHA) of the drill string. During regular horizontal drilling, the drill string rotates, thereby rotating the drill bit and driving the BHA forward. However, when a course correction or turn is desired, the steerable system is operated in a sliding mode in which the drill pipe of the drill string is not rotated and the drill bit is rotated exclusively by the drilling motor. The bent housing steers the drill bit in the desired direction as the drill string slides through the bore, thereby effectuating directional drilling.

However, the modes of regular drilling and sliding present different challenges to the drill system. As the drill string rotates in the regular drilling mode, frictional forces are reduced and more bit weight is typically available for drilling. When drilling in the sliding mode, with the drill pipe of the drill string not rotating, the frictional forces on the drill string are increased, and less weight on bit is typically available for drilling since only the drill bit is rotating. In addition, the frictional forces on the drill string along the side of the horizontal well proportionally increase with the length of the horizontal drill string. Eventually, the friction is so great that the drill string does not effectively slide and therefore, the steering capacity becomes inefficient or ineffective.

The present disclosure is directed to systems and methods that overcome one or more of the shortcomings in the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is an illustration of an apparatus according to one or more aspects of the present disclosure.

FIG. 2 is a perspective view of a drill string of the apparatus of FIG. 1 according to one or more aspects of the present disclosure.

FIG. 3 is a perspective view of a conventional drill string and a drill string according to one or more aspects of the present disclosure.

FIG. 4-1 is a cross-sectional view of a horizontal bore hole and drill pipe during operation.

FIG. 4-2 is a cross-sectional view of a horizontal bore hole and drill pipe during operation according to one or more aspects of the present disclosure.

FIG. 5-1 is a side view of a wellbore and drill string during operation.

FIG. 5-2 is a side view of a wellbore and drill string during operation according to one or more aspects of the present disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.

The present disclosure is directed to apparatuses, such as drill strings, and methods having a unique arrangement that reduces frictional engagement between the drill string and the bore hole enabling BHAs with motors to have a greater effective range, resulting in decreased costs per drilling length. The arrangement increases the drilling range of mud motors because it increases the weight on bit even during slides at greater horizontally drilled depths. It does this by using a lighter mass aluminum pipe with a bent BHA in place of a conventional heavier mass steel pipe. The use of the aluminum pipe in place of the steel pipe in the well bore reduces the normal force acting against the horizontal bore wall, which reduces the overall friction and permits more effect sliding when drill pipe of the drill string is not rotating.

Referring to FIG. 1, illustrated is a schematic view of an apparatus 100 demonstrating one or more aspects of the present disclosure. The apparatus 100 is or includes a land-based drilling rig. However, one or more aspects of the present disclosure are applicable or readily adaptable to any type of drilling rig, such as jack-up rigs, semisubmersibles, drill ships, coil tubing rigs, well service rigs adapted for drilling and/or re-entry operations, and casing drilling rigs, among others within the scope of the present disclosure.

The apparatus 100 includes a mast 105 supporting lifting gear above a rig floor 110. The lifting gear includes a crown block 115 and a traveling block 120. The crown block 115 is coupled at or near the top of the mast 105, and the traveling block 120 hangs from the crown block 115 by a drilling line 125. One end of the drilling line 125 extends from the lifting gear to drawworks 130, which is configured to reel out and reel in the drilling line 125 to cause the traveling block 120 to be lowered and raised relative to the rig floor 110. The other end of the drilling line 125, known as a dead line anchor, is anchored to a fixed position, possibly near the drawworks 130 or elsewhere on the rig.

A hook 135 is attached to the bottom of the traveling block 120. A top drive 140 is suspended from the hook 135. A quill 145 extending from the top drive 140 is attached to a saver sub 150, which is attached to a drill string 155 suspended within a wellbore 160. Alternatively, the quill 145 may be attached to the drill string 155 directly. It should be understood that other conventional techniques for arranging a rig do not require a drilling line, and these are included in the scope of this disclosure.

The drill string 155 includes interconnected sections of drill pipe 165, a bottom hole assembly (BHA) 170, and a drill bit 175. The bottom hole assembly 170 may include stabilizers, drill collars, and/or measurement-while-drilling (MWD) or wireline conveyed instruments, among other components. The drill bit 175, which may also be referred to herein as a tool, is connected to the bottom of the BHA 170 or is otherwise attached to the drill string 155. One or more pumps 180 may deliver drilling fluid to the drill string 155 through a hose or other conduit 185, which may be fluidically and/or actually connected to the top drive 140. This embodiment includes a system 200 that may be referred to as a telescoping washpipe system disposed between the top drive 140 and the quill 145. The system 200 is described more fully further below.

Still referring to FIG. 1, the top drive 140 is used to impart rotary motion to the drill string 155. However, aspects of the present disclosure are also applicable or readily adaptable to implementations utilizing other drive systems, such as a power swivel, a rotary table, a coiled tubing unit, a downhole motor, and/or a conventional rotary rig, among others.

The apparatus 100 also includes a control system 190 configured to control or assist in the control of one or more components of the apparatus 100. For example, the control system 190 may be configured to transmit operational control signals to the drawworks 130, the top drive 140, the BHA 170 and/or the pump 180. The control system 190 may be a stand-alone component installed near the mast 105 and/or other components of the apparatus 100. In some embodiments, the control system 190 is physically displaced at a location separate and apart from the drilling rig.

FIG. 2 shows additional details of the BHA 170. The BHA 170 includes the drill bit 175, a motor 200, and a bent housing 202 proximal of the motor 200 and distal of the drill pipe 165. The drill bit 175 is disposed at the distal-most end of the BHA and likewise the distal most end of the drill string 155 (FIG. 1). The drill bit 175 may be a tricone bit or a cutter bit, depending on the type of geological formation. The motor 200 may be a mud motor known in the art and may be arranged to rotate the drill bit 175 independent of and relative to the drill pipe 165. In some examples, the mud motor 200 comprises a helical rotor with lobes that rotate as high pressure mud is pumped from the surface to drive the drill bit 175. The bent housing 202 includes a first portion 204 and a second portion 206. The first portion 204 may be configured to substantially align with or be concentric with the drill pipe 165. The second portion 206 may be angled or offset from the first portion 204 and the drill pipe 165. Since the drill bit 175 is attached to and extends from the second portion 206, the drill bit 175 is also offset from the first portion 204 and the drill pipe 165. In some embodiments, the bent housing 202 is formed of a single housing that is formed with a bend therein. In other embodiments, the bent housing 202 is formed of different components rigidly fixed to one another to create an angled arrangement.

In the embodiment shown, the motor 200 is disposed between the drill bit 175 and the bent housing 202, and therefore the motor 200 may be coaxial with the drill bit 175. In other embodiments, the motor 200 is arranged to be proximal of the bent housing 202.

In a horizontal application, during standard rotary drilling, the drill rig as the apparatus 100 rotates the drill pipe 165, which in turn, rotates the entire BHA 170 including the bent housing 202. During this standard rotary drilling, the constant rotation of the drill pipe 165 limits the frictional resistance of the drill pipe 165 on the inner wall of the well bore. This increases the weight on bit applied by the drilling rig at the surface of the drill string 155. When a course correction or turn is desired, the drill string 155 is operated in a sliding mode in which the drill pipe 165 is not rotated and the drill bit 175 is rotated independently by the drilling motor 200. Because the drill bit 175 is connected to the second portion 206 of the bent housing 202, and therefore is offset from the direction of the drill pipe 165, driving the drill bit 175 forward results in drilling in a new direction. As the drill bit 175 advances in the offset direction, the drill pipe 165 slides axially through the well bore without rotation, thereby effectuating a slide that results in directional drilling. After the slide, the entire drill string 155, including the drill pipe 165, is rotated again from the drilling rig to perform rotary drilling, which includes again rotating the entire BHA 170, including the bent housing 202.

FIG. 3 shows the drill string 155 including the BHA 170 and the drill pipe 165 disposed adjacent a conventional drill string 250. The conventional drill string 250 includes a BHA 252 and steel drill pipe 254. As will be discussed further below, the range of the conventional drill string 250 may be limited due to excessive buoyancy and mass in the drill pipe 254.

Referring now to the drill string 155, the drill pipe 165 includes an aluminum drill pipe section 224 and a steel drill pipe section 226. The aluminum drill pipe section 224 has a length intended to form a portion of the drill pipe 165 making up a horizontally disposed drill pipe section. In some embodiments, the aluminum drill pipe section 224 extends from a location proximate the BHA 170 to a location between 500 and 10000 feet above the BHA 170. In some embodiments, the drill pipe section 224 extends more than 4000 feet above the BHA 170. In some embodiments, the aluminum drill pipe section 224 extends between about 7000 feet and 8000 feet above the BHA 170. The aluminum drill pipe section 224 may be longer or shorter depending on the length of the desired horizontal wellbore, the depth of the well, and other factors. The aluminum drill pipe section 224 may be formed of a plurality of tubulars having lengths between 30 and 90 feet, for example, connected together to form at least a portion of the drill pipe 165. Other tubular lengths are also contemplated. As used herein, the term “aluminum drill pipe” is intended to include drill pipe of aluminum alloys and includes drill pipe that is at least about 30 weight percent aluminum. In a preferred embodiment, the aluminum content is at least about 50 weight percent. In some embodiments, the aluminum content is at least 70 weight percent. The steel drill pipe section 226 is disposed proximal of the aluminum drill pipe section 224 and may extend from the aluminum drill pipe section 224 to the surface of the well bore. Depending on the well, the steel drill pipe section 226 may extends between 500 and 10000 feet above the aluminum drill pipe section 224. In some embodiments, it extends more than 4000 feet above the aluminum drill pipe section 224. In some embodiments, the steel drill pipe section 226 extends more than 8000 feet above the aluminum drill pipe section 224. Some embodiments include a short length of steel pipe adjacent the BHA 170 connecting the BHA 170 to the aluminum drill pipe section 224.

FIG. 4-1 shows the drill string 250 and FIG. 4-2 shows the drill string 155 in a side view during a well drilling procedure. Referring to these Figures, the drill pipe 254 includes a horizontal portion 260 and a vertical portion 262. The vertical portion 262 may extend from the drilling rig, while the horizontal portion 260 extends from the bottom of the vertical portion. Since the drill string 250 is conventional using steel pipe along the length of the drill string 250, the drill pipe in the horizontal portion 260 is formed of steel tubing. As used herein, a horizontal portion of a drill pipe refers to portions extending an angle less than 45 degrees from horizontal, while the vertical portion of the drill pipe refers to portions extending at an angle less than 45 degrees from vertical.

The drill string 155 in FIG. 4-2 also includes a horizontal portion 270 and a vertical portion 272. In this embodiment, the portion of the drill pipe 165 forming the horizontal portion 270 is the aluminum drill pipe section 224, and the portion of the drill pipe 165 forming the vertical portion 272 is the still drill pipe section 226.

The aluminum drill pipe section 224 of the drill pipe 165 along the horizontal well bore may provide benefits and advantages not obtained using a steel drill pipe section along the horizontal portion of the well bore. Due to its material properties, the aluminum drill pipe section 224 in FIG. 4-2 has greater buoyancy than the steel drill pipe string 254 in FIG. 4-1. This greater buoyancy reduces friction on the drill pipe and increases the weight on bit. This increased weight on bit allows deeper drilling and increased directional control.

This increased drilling capacity and increased directional control may be a direct result of the decreased mass and increased buoyancy of aluminum pipe when compared to steel pipe. For example only, aluminum piping may have a mass in the range of about 2560-2640 kg/m³. Steel may have a mass in the range of about, for example, 7850 kg/m³. Thus, the mass of steel may be about 2.5-3 times the mass of aluminum. For some aluminum alloys, the mass of steel pipes may be about twice that of the aluminum pipes, and therefore, the use of aluminum pipes results in a 50% reduction of weight. While the masses of aluminum and steel are provided, it should be noted that other types of steel or aluminum and aluminum alloys that may be formed into drill pipes may have masses different than those provided. The resultant buoyancy and the reduced friction resulting from the aluminum pipe are described with reference to FIGS. 5-1 and 5-2.

FIGS. 5-1 and 5-2 respectively show cross-sectional views taken along a horizontal portion of the drill pipes 254, 165 from FIGS. 4-1 and 4-2 within respective well bores 280, 282. Accordingly, FIG. 5-1 shows a steel pipe of the conventional drill pipe 254, and FIG. 5-2 shows an aluminum drill pipe section 224 of the drill pipe 165. For explanation of FIGS. 5-1 and 5-2, the operation of a pump is discussed below.

In use, drilling fluid, referenced as mud, is pumped down the inner diameter of the drill pipes 165, 254 at high pressure. It flows back toward the surface along the outer diameter of the drill pipe 165, 254 within wellbores respectively referenced as 280, 282 in FIGS. 5-1 and 5-2. Accordingly, even in the horizontal section of a drilling run, the boreholes 280, 282 are filled with mud as it returns to the surface, also carrying cuttings and material from the geological formation. FIG. 5-1 shows the conventional steel drill pipe 254 in the horizontal position. For comparison, FIG. 5-2 shows the drill sting 155 with the aluminum pipe in the horizontal position. The steel pipe drill pipe in FIG. 5-1 has a mass greater than the aluminum pipe drill pipe 224 shown in FIG. 5-2. As such, it has less buoyancy and rides lower in the mud within the well bore 280. In contrast, because of its comparatively lower mass, the aluminum pipe section 224 rides higher in the mud within the well bore 282. Because of its greater mass and less buoyancy, the steel drill pipe has greater frictional resistance to sliding with the wellbore wall than the aluminum drill pipe section 224 when in the horizontal position. Likewise, because of its lower mass and greater buoyancy, the aluminum drill pipe section 224 has less frictional resistance to sliding within the wellbore wall than the aluminum drill pipe section 224 in the horizontal run.

Because of its lower mass, the aluminum drill pipe section 224 has a level of buoyancy in the drilling mud greater than the level of buoyancy of the steel drilling pipe 254. This in turn directly reduces the frictional resistance to axial sliding motion when the drill pipe advances by linear sliding instead of advancing while the drill pipe also rotates.

In mathematical terms, friction is determined by the equation:

F_(friction)=μF_(normal)

Where μ is the coefficient of friction and F_(normal) is dependent on F=mg, where m is mass and g is the acceleration due to gravity. Because steel pipe has a higher mass, F_(normal) for steel pipe is greater than F_(normal) for aluminum pipe. Since F_(normal) is lower for aluminum pipe, the F_(friction) is also lower for aluminum pipe. Less friction results in greater weight on bit applied at the surface or by the weight of the drill pipe in the vertical section. This in turn increases the distance that the BHA can travel before friction overcomes the ability to effectively drill or effectively directionally steer the drill string. This result is illustrated in FIGS. 4-1 and 4-2 showing the horizontal portion of the drill string 155 in FIG. 4-2 having a length much greater than the horizontal portion of the drill string 250 in FIG. 4-1.

The apparatus 100 (FIG. 1) as a drilling rig may be used to drill subterranean formations using the drill string 155 with the aluminum drill pipe portion 224. It begins by building the drill pipe 165, one tubular at a time, at the drilling rig. The rig may drive the BHA 170 into the well hole. Drill pipe 165 formed of an aluminum tubular is then attached directly to or proximate the BHA 170 to form the drill string 155. The drill string 155, including the drill pipe 165, the drill bit 175, the motor 200, and the bent housing 202 is rotated to drive the BHA 170 deeper into the ground. Additional aluminum tubulars may be added to continue to build the drill string 155 and advance it into the well bore. In some aspects the length of the aluminum drill pipe section 224 may correspond to the length of the horizontal drilling length called out in the drilling plan. When the BHA 170 reaches a desired depth, the BHA 170 may be rotated consistent with the drilling plan to drill in a horizontal direction and create a horizontal wellbore. This may be done by alternatingly performing rotary drilling and slides. As indicated above, rotary drilling is rotating the entire drill string 155 and slides are performed by rotating the drill bit 175 with the motor 200 to achieve directional drilling while not rotating the drill pipe 165 and the bent housing 202.

In a slide, since the bent housing 202 maintains the drill bit 175 at an orientation offset from the drill pipe 165, the drill bit 175 drills in the offset direction, creating a bend in the wellbore. As the drill string 155 advances without rotating, it axially slides in the wellbore. Slides and rotary drilling may be incrementally repeated until the well bore is advancing in a horizontal direction consistent with the drilling plan.

With the wellbore extending in the horizontal direction, the aluminum drill pipe section 224 has a greater buoyancy and, because of its lower mass, less friction than a conventional steel drill pipe string. As the drill string 155 progresses through subterranean formations, it may again become necessary to make directional adjustments. In the same manner discusses above, this is done by performing additional slides by ceasing rotation of the drill pipe 165 and bent housing 202, and rotating the drill FIG. bit 175 with the motor 200 to cause the drill string 155 to advance in a different direction. As the drill string 155 slides forward in the axial direction without rotating, the aluminum drill pipe section 224 may advance with a lower level of friction than a steel pipe string. Rotary drilling may be performed in the new direction by rotating the drill sting 155 to again rotate the entire BHA.

As the pipe string 155 continues to be built, steel tubulars may be added at the proximal end of the drill string 155. These steel tubulars, having a greater mass than the aluminum tubulars, may add to weight on bit as they are advance into the vertical portion of the wellbore.

Because the aluminum drill pipe 165 has decreased mass compared to conventional steel piping, when drilling horizontally with the BHA 170 including the bent housing 202, the drill string 155 may be able to advance further than has been achieved in prior art systems. This may result in more efficient drilling costs and may increase the range of current conventional drill strings.

In view of all of the above and the figures, one of ordinary skill in the art will readily recognize that the present disclosure introduces an apparatus including a drill bit configured to penetrate a subterranean formation and a bent housing portion disposed proximal the drill bit. The bent housing may have a first housing section and a second housing section, with the second housing section offsetting the drill bit from the first housing section. The apparatus also may include a mud motor disposed proximal of the drill bit and configured to rotate the drill bit independent of rotation of the bent housing, and may include a drill pipe extending in a wellbore, the drill pipe extending from a surface of the wellbore toward the first housing section of the bent portion and being rotatable to rotate the drill bit, the bent housing portion, and the mud motor. The drill pipe may include a horizontally disposed section in the well bore, with the horizontally disposed section comprising an aluminum pipe section.

In an aspect, the aluminum pipe section in the horizontally disposed section has a length greater than 4000 feet. In an aspect, the drill pipe comprises a vertically disposed portion formed of a steel pipe section. In an aspect, the drill pipe comprises a steel pipe section disposed proximal of the aluminum pipe section. In an aspect, the drill pipe comprises a section having a first buoyancy and a section having a second buoyancy, the first buoyancy being greater than the second buoyancy. In an aspect, the drill pipe comprises a section formed of a material having a first mass and a section formed of a material having a second mass, the first mass being greater than the second mass. In an aspect, the bent housing portion comprises multiple components fixed in an angled arrangement.

The present disclosure also introduces a method including drilling a bore hole in a horizontal direction with a drill bit, a bent housing portion, and a mud motor by rotating the drill bit, the bent housing portion, and the mud motor with drill pipe comprising an aluminum pipe section; stopping rotation of the drill pipe; performing a slide by rotating the drill bit with the mud motor to advance the drill bit, the bent housing portion, the mud motor, and the drill pipe in the borehole so that the aluminum pipe section moves axially along the bore hole in the horizontal direction; and continuing to drill the bore hole by rotating the drill bit, the bent housing portion, and the mud motor with the drill pipe.

In an aspect, the method includes building a leading portion of the drill pipe with the aluminum pipe section; and building a trailing portion of the drill pipe with a steel pipe section. In an aspect, building a leading portion the drill pipe with the aluminum pipe section comprises building at least 4000 feet of the drill pipe with the aluminum pipe section. In an aspect, building a trailing portion of the drill pipe with the steel pipe section comprises building at least 4000 feet of the drill pipe with the steel pipe section. In an aspect, the method includes rotating the drill pipe with a top drive. In an aspect, the method includes rotating the aluminum pipe section with a portion of the drill pipe formed of a steel pipe section. In an aspect, the steel pipe section is disposed in a vertical portion of the wellbore.

In an aspect, the method includes forming a horizontal segment of a wellbore by rotating a bottom hole assembly with aluminum drill pipe, the bottom hole assembly comprising a drill bit and a bent housing portion; directionally steering the bottom hole assembly by rotating the drill bit independent of the bent housing portion and axially sliding the aluminum drill pipe along the horizontal segment of the wellbore without rotating the aluminum drill pipe; and continuing to drill wellbore by rotating the bottom hole assembly with the aluminum drill pipe.

In an aspect, forming the horizontal segment includes forming the horizontal segment at least 4000 feet in length with at least 4000 feet of aluminum drill pipe. In an aspect, the method includes building a leading portion of a drill pipe with the aluminum drill pipe; and building a trailing potion of the drill pipe with steel drill pipe. In an aspect, building a leading portion the drill pipe with the aluminum drill pipe comprises building at least 4000 feet of the drill pipe with the aluminum drill pipe. In an aspect, building a trailing potion of the drill pipe with the steel drill pipe comprises building at least 4000 feet of the drill pipe with the steel drill pipe. In an aspect, the method includes rotating the aluminum drill pipe with a top drive. In an aspect, the method includes rotating the aluminum drill pipe with a steel drill pipe. In an aspect, the steel drill pipe is disposed in a vertical portion of the wellbore.

The foregoing outlines features of several embodiments so that a person of ordinary skill in the art may better understand the aspects of the present disclosure. Such features may be replaced by any one of numerous equivalent alternatives, only some of which are disclosed herein. One of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. One of ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

The Abstract at the end of this disclosure is provided to comply with 37 C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Moreover, it is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the word “means” together with an associated function. 

What is claimed is:
 1. An apparatus, comprising: a drill bit configured to penetrate a subterranean formation; a bent housing portion disposed proximal the drill bit, the bent housing having a first housing section and a second housing section, the second housing section offsetting the drill bit from the first housing section; a mud motor disposed proximal of the drill bit and configured to rotate the drill bit independent of rotation of the bent housing; a drill pipe extending in a well bore, the drill pipe extending from a surface of the well bore toward the first housing section of the bent portion and being rotatable to rotate the drill bit, the bent housing portion, and the mud motor, the drill pipe comprising a horizontally disposed section in the well bore, the horizontally disposed section comprising an aluminum pipe section.
 2. The apparatus of claim 1, wherein the aluminum pipe section in the horizontally disposed section has a length greater than 4000 feet.
 3. The apparatus of claim 1, wherein the drill pipe comprises a vertically disposed portion formed of a steel pipe section.
 4. The apparatus of claim 1, wherein the drill pipe comprises a steel pipe section disposed proximal of the aluminum pipe section.
 5. The apparatus of claim 1, wherein the drill pipe comprises a section having a first buoyancy and a second section having a second buoyancy, the first buoyancy being greater than the second buoyancy.
 6. The apparatus of claim 1, wherein the drill pipe comprises a section formed of a material having a first mass and a second section formed of a material having a second mass, the first mass being greater than the second mass.
 7. The apparatus of claim 1, wherein the bent housing portion comprises multiple components fixed in an angled arrangement.
 8. A method, comprising: drilling a bore hole in a horizontal direction with a drill bit, a bent housing portion, and a mud motor by rotating the drill bit, the bent housing portion, and the mud motor with drill pipe comprising an aluminum pipe section; stopping rotation of the drill pipe; performing a slide by rotating the drill bit with the mud motor to advance the drill bit, the bent housing portion, the mud motor, and the drill pipe in the borehole, so that the aluminum pipe section moves axially along the bore hole in the horizontal direction without rotating; and continuing to drill the bore hole by rotating the drill bit, the bent housing portion, and the mud motor with the drill pipe.
 9. The method of claim 8, comprising: building a leading portion of the drill pipe with the aluminum pipe section; and building a trailing portion of the drill pipe with a steel pipe section.
 10. The method of claim 9, wherein building a leading portion the drill pipe with the aluminum pipe section comprises building at least 4000 feet of the drill pipe with the aluminum pipe section.
 11. The method of claim 10, wherein building a trailing portion of the drill pipe with the steel pipe section comprises building at least 4000 feet of the drill pipe with the steel pipe section.
 12. The method of claim 8, comprising rotating the drill pipe with a top drive.
 13. The method of claim 8, comprising rotating the aluminum pipe section with a portion of the drill pipe formed of a steel pipe section.
 14. The method of claim 13, wherein the steel pipe section is disposed in a vertical portion of the well bore.
 15. A method, comprising: forming a horizontal segment of a well bore by rotating a bottom hole assembly with aluminum drill pipe, the bottom hole assembly comprising a drill bit and a bent housing portion; directionally steering the bottom hole assembly by rotating the drill bit independent of the bent housing portion and axially sliding the aluminum drill pipe along the horizontal segment of the well bore without rotating the aluminum drill pipe; and continuing to drill well bore by rotating the bottom hole assembly with the aluminum drill pipe.
 16. The method of claim 15, wherein forming the horizontal segment includes forming the horizontal segment at least 4000 feet in length with at least 4000 feet of aluminum drill pipe.
 17. The method of claim 15, comprising: building a leading portion of a drill pipe with the aluminum drill pipe; and building a trailing potion of the drill pipe with steel drill pipe.
 18. The method of claim 17, wherein building a leading portion the drill pipe with the aluminum drill pipe comprises building at least 4000 feet of the drill pipe with the aluminum drill pipe.
 19. The method of claim 18, wherein building a trailing potion of the drill pipe with the steel drill pipe comprises building at least 4000 feet of the drill pipe with the steel drill pipe.
 20. The method of claim 15, comprising rotating the aluminum drill pipe with a top drive.
 21. The method of claim 15, comprising rotating the aluminum drill pipe with a steel drill pipe.
 22. The method of claim 21, wherein the steel drill pipe is disposed in a vertical portion of the well bore. 